Michael A. McFadden

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We examined the ability of radiologists to detect pulmonary nodules in computed radiographic (CR) chest images subjected to lossy image compression. Low-contrast 1-cm diameter targets simulating noncalcified pulmonary nodules were introduced into clinical images and presented to ten radiologists in a series of two-alternative forced-choice (2AFC) observer(More)
Contrast-detail (CD) analysis was used to compare the low-contrast detectability of computed radiography (CR) and screen-film (SF) as applied to the task of adult chest radiography. A phantom was constructed and imaged using the same exposure factors throughout all experiments. Within-observer variance, between-observer variance, and image sample variance(More)
Mammography and accurate microcalcification detection require very good spatial resolution. We have compared the diagnostic capabilities of reduced-exposure, third-generation, 5 cycles/mm computed radiography (CR) phosphor plates with conventional screen-film in 67 patients. No difference in diagnostic accuracy was detected. The digital characteristics of(More)
The goal of the study was to compare a cathode-ray-tube (CRT) digital display with film by using task-dependent image quality assessment methods. Contrast-detail analysis was utilized. Human observers performed a simple detection task, specifically, detecting a pillbox target in a uniform Poisson field, using either film or a digital display that employed a(More)
A new dual-ported, floating-point, digital signal processor has been evaluated for compressing 512 and 1,024 digital radiographic images using a full-frame, two-dimensional, discrete cosine transform (2D-DCT). The floating point digital signal processor operates at 49.5 million floating point instructions per second (MFLOPS). The level of compression can be(More)
A prospective, double-blind, placebo-controlled, randomized clinical trial was conducted to study the efficacy of oral ketamine for providing sedation and analgesia to children during laceration repair. Thirty children between the ages of one and seven years with lacerations that required suturing were randomly assigned to receive either oral ketamine (10(More)
Technologic advances such as total parenteral nutrition have prolonged the lives of individuals with short-bowel syndrome who previously would not have survived. However, the day-to-day management of these patients presents a significant challenge to those who take care of them. Providing medications on either an acute or chronic basis without the use of(More)
A contrast-detail (CD) experiment was performed to study the effect of lossy compression on computed radiographic (CR) images. Digital CR images of a phantom were compressed by quantizing the full-frame discrete cosine transform and Huffman encoding the result. Since low-contrast detectability is directly linked to an important radiological task, namely,(More)
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